From Simi Valley, California, December 2011's totally eclipsed Moon hung just a few degrees above the western horizon.
There’s a penumbral lunar eclipse happening across all of North America the evening of Friday, February 10th.
The full moon will get noticeably less bright as it moves out of the sun’s direct light and into the Earth’s shadow shortly afternoon sundown on the East Coast
What Exactly Is A Penumbral Eclipse?
The shadow of the Earth can be divided into two distinctive parts: the umbra and penumbra.
Within the umbra, there is no direct light from the sun. However, as a result of the Sun’s large size compared to the Earth, some solar illumination “bends” around the earth and is only partially blocked in the outer portion of the Earth’s shadow. That outer portion is called the penumbra.
Think of the shadow the Earth makes from the sun’s light as looking a bit like a dart board— with the dark umbra as the bulls eye and the less dark penumbra as the first circle surrounding the bulls eye.
A penumbral eclipse occurs when the moon passes through the Earth’s penumbra. The penumbra causes a subtle but clearly visible darkening of the moon’s surface.
A special type of penumbral eclipse is a total penumbral eclipse, during which the Moon lies exclusively within the Earth’s penumbra. Total penumbral eclipses are rare, and when these occur, that portion of the moon which is closest to the umbra can appear somewhat darker than the rest of the moon.
During Friday’s eclipse most, but not quite all, of the moon will enter the penumbra and observers should see a distinct darkening of the moon as the Earth’s shadow reduces the amount of sunlight hitting the moon.
It’s Safe And Easy To Observe
Unlike a solar eclipse, which can be viewed only from a certain relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of the Earth. A lunar eclipse lasts for a few hours, whereas a total solar eclipse lasts for only a few minutes at any given place, due to the smaller size of the Moon’s shadow.
Also unlike solar eclipses, lunar eclipses are safe to view without any eye protection or special precautions, as they are dimmer than the full moon.
It Starts Around Dinner Time
The eclipse will start to be noticeable a bit after 6:00 PM on the East coast (it actually begins at 5:32 PM) when the Moon’s leading edge enters Earth’s penumbra. You can do the math and see the timing is a little less friendly for readers on the West coast— but things should be be quite visible if the sky is clear.
The eclipse will last more than four hours and will be visible early Saturday in Europe, Africa and western Asia as well as North America.
Initially, the affect is not especially noticeable. You won’t start to see a dusky fringe along the Moon’s leading edge (known to astronomers as its “celestial east”) until the the moon intrudes about halfway across the penumbra. But keep an eye on the moon and your patience will be rewarded.
Watch Online If Your Local Weather Doesn’t Cooperate
If the weather isn’t so nice, or you just prefer to watch from the comfort of home, SLOOH will broadcast a live webcast. The webcast will start at 5:30 PM. EDT and you can watch it by clicking here.
There’s A Comet Out There Too!
Comet 45P will zip by Earth early Saturday morning. It will be an extremely close encounter as these things go, passing within 7.7 million miles (12.4 million kilometers) of Earth moving at 14.2 miles per second, or an eye-popping 51,120 mph.
The comet, glowing green, will be visible in the constellation Hercules. Binoculars and telescopes will help in the search as it will be quite difficult to see unassisted.
Astronomers have been tracking Comet 45P for the past couple of months. The icy ball — an estimated mile across — comes around every five years. It’s officially known as Comet 45P/Honda-Mrkos-Pajdusakova, named after the Japanese, Czech and Slovak astronomers who discovered it in 1948. The letter P stands for periodic, meaning it’s a recurring visitor to the inner solar system.
Regardless of the hour, you’ll not regret making time to catch one of nature’s best shows!
What are your plans for watching the eclipse? Or catching the comet? We’re planning to keep the kids up here…